I posted this in the Assetto mod thread as well, but having driven it virtually, the track is more in the challenging category than nice and flowing. The first half is dominated by those 2 long straights (each measuring 800m, so same length as the backstraight of Suzuka from Spoon to 130R). You can really stretch your supercar's legs there. The hairpin's entrance is awkward to say the least, I certainly braked way too late on a few occasions as it looks more open than it actually is. They tried to copy Turkey's quad apex Turn 8 but didn't have the space to do it, so it ends up feeling slow and cumbersome. After the backstraight is the most interesting corner in my opinion. An uphill triple apex high speed corner that progressively tightens. And then after that is the "touge" sector. Lots of repeating esses with tricky blind off camber corners. It's a real challenge trying to nail every apex but it definitely doesn't feel intuitive or flowing to drive like a regular mountain road (ironically, there are lots of nice touges leading to the track itself. Save your money and just drive there instead
). Closest thing in Gran Turismo would be if you try driving the mountain section of Bathurst backwards, and imagine the walls are pushed back and replaced with tarmac run off.
Here's an onboard at high speed of the track in AC. This was way back when the track was just announced so the scenery and run off areas don't look exactly the same, but the layout is still accurate.
IMO, the track would flow a lot better in reverse and if the corners are banked instead of off camber. Also replace the weird 270 degree hairpin with a normal 180 degree one. But I think that would raise the average speed and require more runoff for safety, which they don't have being in the middle of a mountain.
I'd love to see it in GT someday (along with returning Ascari Race Resort and a proper touge track), but it's going to be a weird track to race on. Slow cars are going to struggle with the uphill bits, but faster cars are going to have trouble racing side by side. So it will just end up being a supercar hotlapping track (which is what it's made for IRL).
Final note, maybe Polyphony should try asking Tilke to design an original track with no restrictions sometimes. His F1 tracks have a reputation for being boring but that's because of rules and regulations dictating certain parameters and the topography he has to work with. When allowed a bit more freedom, we get real gems like Magarigawa, Bilster Berg and Monticello Motor Club.